While a judge granted bail to the three railway workers accused of criminal negligence in the Lac-Mégantic disaster on Tuesday, a provincial prosecutor said there is insufficient evidence to justify charges against anyone else.

One of the most persistent questions in regard to Lac-Mégantic has been whether Ed Burkhardt, the railway executive at the top of the Montreal, Maine & Atlantic Railway before the July 7 crash, would face criminal charges. Prosecutor René Verret said the investigation by the Sûreté du Québec is now closed.

“The decision to bring charges belongs to the prosecutors and remains confidential. But the evidence presented by the police allowed these charges to be laid,” Mr. Verret told reporters in Lac-Mégantic.

Forty-seven people died in the early hours of July 6 last year when a runaway MM&A train carrying crude oil crashed into town and exploded.

Thomas Harding, the engineer who was operating the train before it crashed, Jean Demaître, the onetime manager of train operations and Richard Labrie, company controller, each face 47 charges of criminal negligence causing death, along with the railway.

Mr. Harding’s lawyer and union representative were outraged that the engineer was arrested at gunpoint by a tactical squad at his home and in front of his son Monday evening, despite repeated offers to turn himself in.

“It’s like we’ve returned to the middle ages. I’ve never seen a circus like it. What kind of society are we living in?” said Daniel Roy, an official from the metalworkers’ union that represents MM&A workers. “Do we really need to rush into his home, drag him to the ground, handcuff him, and drag him back to the town square in Mégantic?”

Meanwhile the real danger is just fine in the United States.”

Mr. Burkhardt, the U.S.-based railway executive, did not return several calls from the Globe and Mail. A worker in his office said he was travelling in Europe.

Mr. Verret said an arrest was necessary because a judge had to approve the release conditions of the three men who were paraded in handcuffs before a crowd and cameras before their appearance Tuesday afternoon.

“There is the gravity of the charges which is a factor to consider, and the fact we needed certain conditions (of release) established,” he said. “That’s why we proceeded the way we did.”

The Sûreté du Québec declined to address their arrest tactics.

Mr. Verret also said Lac-Mégantic is the judicial district where the alleged crimes took place, even if the town only has a temporary courthouse in a converted gymnasium. “It’s an important principle,” Mr. Verret said.

A heavily-armed tactical squad showed up with sirens blaring while Mr. Harding and his son were working on a boat. The pair and a family friend were forced to drop to the ground so they could be handcuffed, the defence lawyer said.

“They’re trying to swat a fly with a cannon. It was like an invasion,” Mr. Walsh told Radio-Canada Tuesday morning.

He said he had repeatedly told the Crown to issue summons “and Mr. Harding would show up, as he has always done before every time he was questioned [by police].”

Sergeant Aurélie Guindon, a spokeswoman for the Sûreté du Québec, said the force would not comment on Mr. Walsh’s remarks.

Mr. Walsh said he did not know if the three men were charged jointly. They may need separate court proceedings because Mr. Harding is anglophone and could request a trial in English while the other two are francophones.